Design of chemical sensor arrays for monitoring disposal sites on the ocean floor

We develop detection methods for automatic environmental monitoring of disposal sites on the deep ocean floor using chemical sensor arrays. Such sites have been proposed for the relocation of dredge materials from harbors and shipping channels; the monitoring is used to detect possible release of pollutants at the site. We model the underwater transport of the pollutants as a diffusion process, and obtain a measurement model by exploiting the spatial and temporal evolution of the associated concentration distribution. The detection problem is defined by a one side hypothesis test for the case of multiple sources. We derive two detectors, the generalized likelihood ratio (GLR) test and the mean detector, and determine their performance in terms of the probabilities of false alarm and detection. The results are applied to the design of chemical sensor arrays satisfying criteria specified in terms of these probabilities, and to optimally select numbers of sensors and time samples. Numerical examples are used to demonstrate the applicability of our results.